1. Field of the Invention
This invention relates to signal subtraction or moving target indication and particularly to a signal subtraction system utilizing charge coupled devices that substantially eliminates the common mode error, reduces power and provides high bandwidth.
2. Description of the Prior Art
Conventionally, to provide a difference or subtraction output function with charge coupled devices, an operational amplifier and a sample and hold circuit were required. However, the amplifier has typically 60 db common mode error for precision large size and high power operational amplifiers and requires considerable space and heat dissipation. A system utilizing CCD techniques that would provide a difference or subtraction of charges without requiring external circuitry would be a substantial advantage to the art.